reactos/lib/drivers/sound/mmixer/mixer.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS Kernel Streaming
   4  * FILE:            lib/drivers/sound/mmixer/mmixer.c
   5  * PURPOSE:         Mixer Handling Functions
   6  * PROGRAMMER:      Johannes Anderwald
   7  */
   8
   9
  10
  11 #include "priv.h"
  12
  13 MIXER_STATUS
  14 MMixerInitialize(
  15     IN PMIXER_CONTEXT MixerContext,
  16     IN PMIXER_ENUM EnumFunction,
  17     IN PVOID EnumContext)
  18 {
  19     MIXER_STATUS Status;
  20     HANDLE hMixer;
  21     ULONG DeviceIndex, Count;
  22     LPWSTR DeviceName;
  23
  24     if (!MixerContext || !EnumFunction || !EnumContext)
  25     {
  26         // invalid parameter
  27         return MM_STATUS_INVALID_PARAMETER;
  28     }
  29
  30     if (!MixerContext->Alloc || !MixerContext->Control || !MixerContext->Free)
  31     {
  32         // invalid parameter
  33         return MM_STATUS_INVALID_PARAMETER;
  34     }
  35
  36
  37     // start enumerating all available devices
  38     Count = 0;
  39     DeviceIndex = 0;
  40
  41     do
  42     {
  43         // enumerate a device
  44         Status = EnumFunction(EnumContext, DeviceIndex, &DeviceName, &hMixer);
  45
  46         if (Status != MM_STATUS_SUCCESS)
  47         {
  48             //check error code
  49             if (Status != MM_STATUS_NO_MORE_DEVICES)
  50             {
  51                 // enumeration has failed
  52                 return Status;
  53             }
  54             // last device
  55             break;
  56         }
  57
  58
  59         // increment device index
  60         DeviceIndex++;
  61
  62         Status = MMixerSetupFilter(MixerContext, hMixer, &Count, DeviceName);
  63
  64         if (Status != MM_STATUS_SUCCESS)
  65             break;
  66
  67     }while(TRUE);
  68
  69     // done
  70     return Status;
  71 }
  72
  73